Korean director Bong Joon-ho's uproarious new film about a gigantic sea monster is beautifully and even subtly made. Maybe even a bit too beautifully and subtly. Despite the extraordinary CGI scenes of a fully fledged monster attacking the big city, harking back to the glory days of Godzilla and Kong, I found something oddly unscary about the creature itself. And the film, though intriguing, doesn't quite have the raw, crazy showmanship of an old-fashioned monster movie. The creature, as it emerges from the Han river to pulverise the citizens of Seoul in South Korea, is awe-inspiring, exotic, even a touch humorous. But not terrifying like, say, Ridley Scott's Alien.

However, Bong's movie is not merely about spectacle: there is a dash of anti-American satire in the fact that the monster was caused by pollution from a US military base, whose top brass insist on a heavy-handed imposition of "quarantine" as the panic spreads. Could it be that the Americans, accustomed to treating South Korea as a buffer zone against Kim Jong-il's rogue state to the north, are the real aliens, the real monsters?

Satire is subservient, though, to the drama of a family changed forever by the monster's appearance. Song Kang-ho, who played the heavy-set cop in the director's much-admired 2003 thriller Memories of Murder, here plays a pathetic layabout who must redeem himself when the monster grabs his young daughter from the riverbank and swims off with her. The Ballardian nightmare of the anarchic monster playing havoc with the cool, rational technopolis is always riveting.